Datasheet

DISPLAY PRECISION
Don’t be fooled by the integer of 27 shown for the angle in Figure 1.6. The actual angle may
be different. Why? Because the default precision for angle display is 0, which means all angles
are rounded to a whole number for display purposes only. If you change the angular preci-
sion using either the variable AUPREC or the Units dialog box, you’ll see the angle in this case
is actually 27.37591770°. This often fools people when linear distances are displayed, as well.
(Linear precision can be set with the LUPREC variable or the Units dialog box.) Display
This doesn’t affect the actual precision AutoCAD uses for calculations. All calculations are
done to 15 decimal places no matter how the results are displayed.
5. Pick either the Column Offset or Unit Distance button, which results in the prompt
Specify distance between columns.
6. Using the Endpoint object snap, select each end of the spline once again. Doing so
returns a distance this time and places that value in the window. Click the Preview
button; if you like the results, you’re done.
COMMAND-LINE VERSION OF ARRAY
You may decide to automate a process like this using AutoLISP. In that case, you need to
follow these steps, using the command-line version of the ARRAY command:
1. Run the UCS command, and type Z↵ to rotate a UCS around the Z axis. You may
have noticed that Z isn’t displayed as an option. It’s a hidden option of UCS.
2. Select the two endpoints of the object, in this case a spline, to indicate the angle of
rotation.
3. Run the ARRAY command at the command prompt (
-AR), and select the spline you
want to array at an angle.
4. Press the Enter key at the Enter the type of array [Rectangular/Polar] <R> prompt.
5. Specify one row and four columns, and you’ll be prompted to give the distance only
between columns.
6. Select the two endpoints of the spline again to give the exact distance.
7. Use the UCS command to return to the World Coordinate System (WCS).
Any time you’re prompted for a distance or an angle in AutoCAD, you can select points on
the screen instead of typing them in. Doing so is both fast and accurate. When you start cre-
ating your own commands in AutoLISP, you can use specific functions to make your pro-
grams behave the same way.
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